Up to now, as everyone knows, the Long Term Evolution (LTE) system is deployed in licensed carriers for operation. However, with the evolution of the LTE system, recently some companies (such as America Qualcomm Corporation) put forward a suggestion of carrying out a study on deployment of the LTE system in unlicensed carriers. However, up to now, it has not been accepted by relevant organizations of LTE and no project is established.
America Qualcomm Corporation gives the following main project establishment reasons: with the rapid increase of data service, licensed spectrums cannot bear such huge data volume in near future; and thus it is suggested that deploying LTE in unlicensed spectrum resources and sharing data traffic in licensed carriers should be considered through unlicensed spectrums.
If the LTE system operates in unlicensed carriers, according to regulatory policies of all countries on unlicensed carriers, when the LTE system uses unlicensed carriers, monitoring needs to be performed firstly and the unlicensed carriers shall not be used by the LTE system until it is monitored that the unlicensed carriers are idle. As a result, how to design a reasonable monitoring mechanism aiming at the LTE system to enable the LTE system to have the optimum efficiency of monitoring and obtaining the unlicensed carriers is a problem which needs to be urgently solved at present.